Note 17 - Revenue (Details)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Oil Revenue Disclosure [Abstract]
Royalty Rate	5.00%bpz_RoyaltyRate	5.00%bpz_RoyaltyRate	5.00%bpz_RoyaltyRate

Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property, stated as a percentage.

No definition available.

Name:	bpz_RoyaltyRate
Namespace Prefix:	bpz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration